A composite quasi-solid electrolyte is prepared by adding a layered Mg-Al hydrotalcite (LMAH) into the iodide/triiodide quasi-solid electrolyte including 4-tert-butylpyridine, which obviously improves the photovoltaic properties of quasi-solid dye-sensitized solar cells (DSSCs). When adding 5 wt% LMAH, the maximum photovoltaic conversion efficiency of DSSC is obtained, which reaches almost three times as large as that without LMAH. This enhancement effect is primarily explained by studying the nyquist spectrums, limiting current density, diffusion coefficient and photovoltaic conversion efficiency. (c) 2013 The Electrochemical Society. All rights reserved.